Runway check · 60 seconds
Startup runway calculator
Do you know your runway to the month? Type the numbers you already know. See how long your cash lasts, when to raise, and the deadlines you are carrying.
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Your numbers
Results update as you typeSee your predictions and deadlines
Your runway is above. Below, blurred until you enter an email: when to start raising, cash over 24 months in three scenarios, your burn multiple, and the tax deadlines your company is carrying, with days left.
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Predictions
Cash over the next 24 months
Hover for month by month
Three ways it could go
| Scenario | Assumes | Runway | Zero cash | Raise by |
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Deadlines you're probably carrying
How this is calculated
- Each month: cash + MRR × (1 + growth)^month − gross spend − hires in seat × (loaded cost ÷ 12) − (new MRR from growth) × (1 − gross margin). Revenue counts in full because today's cost of serving customers is already inside your spend; only revenue added by growth carries an extra cost of serving.
- Conservative: spend +15%, growth 0%, hires start now. Optimistic: spend −15%, growth × 1.5, hires start two months later. Base: your inputs.
- Burn multiple = net burn ÷ net new ARR added this month. Under 1 is strong, 1 to 2 is normal at seed, over 2 needs a reason.
- "Default alive" means revenue growth reaches break-even before cash runs out on the base path.
- Deadlines are the general rule for a US C-corp, not advice for your case. Delaware franchise tax: the assumed par value method usually gives the $400 minimum for a typical startup; the default notice uses the authorized shares method and is usually far higher.
How runway works
What the numbers mean.
Runway is months of cash at your current net burn
Take the cash in your operating and sweep accounts today. Subtract what leaves the account in a typical month: payroll, contractors, cloud and inference, rent, software, fees. Add back what comes in. The result is net burn, and cash divided by net burn is runway in months. A company with $600,000 in the bank, $50,000 of monthly spend and $10,000 of monthly revenue burns $40,000 net and has 15 months.
That simple division is right for a company whose numbers do not move. Most startups' numbers do move, so this calculator walks forward one month at a time. Revenue compounds at the growth rate you enter. Planned hires start costing money in the month you pick. Revenue you add through growth carries an extra cost of serving those customers, at one minus your gross margin; the cost of serving today's customers is already inside your spend, so it is not counted twice.
Three scenarios, because one line is a guess
The base case is your numbers as typed. The conservative case adds fifteen percent to spend, drops revenue growth to zero and starts every planned hire now. The optimistic case trims spend by fifteen percent, multiplies growth by one and a half and delays hires by two months. Real outcomes usually land between conservative and base, which is why the conservative date is the one to plan a raise around.
When to start raising
A seed or Series A raise takes three to six months from the first meeting to money in the bank. Founders who start with less than six months of cash left negotiate from weakness and accept worse terms. So the calculator marks the month that is six months before the base case runs out of cash. If that month is already here, the answer is now. After a round closes, the usual target is 18 to 24 months of runway, enough to reach the milestones the next round will be priced on.
Burn multiple and default alive
Burn multiple is net burn divided by the net new annual recurring revenue added in the same month. It answers a question runway does not: is the money buying growth? Under one is efficient, one to two is normal at seed, and above two means each dollar of ARR is expensive. Default alive, a term from Paul Graham, asks whether revenue growth reaches break-even before the cash runs out. If it does, the company survives without another raise; if not, it needs a raise or a cut, and the sooner that is decided the more options remain.
The deadlines a US C-corp carries
Runway is not the only clock. A Delaware C-corp owes its franchise tax and annual report on March 1, its federal return on April 15 unless extended, and Forms 1099-NEC for contractors by January 31. A company with a foreign founder or a 25 percent foreign shareholder files Form 5472 with its return, and the penalty for missing it starts at $25,000. Hiring in a new state means an employer registration before the first payroll there. The calculator lists the ones that apply to the boxes you tick, counted down from today. These are the general rules, not advice for your situation; whoever prepares your return confirms them.
Questions founders ask
How is startup runway calculated?
Runway in months is cash in the bank divided by net burn, where net burn is what leaves the account each month minus what comes in. This calculator goes a step further and walks month by month, so revenue growth, planned hires and the cost of serving new customers change the answer over time instead of being averaged away.
What is a good amount of runway for a seed-stage startup?
Most investors and founders work with 18 to 24 months after a round closes. The reason is timing: a seed or Series A raise usually takes three to six months from first meeting to money in the bank, and you want to start it with at least six months of cash left so you are not negotiating from weakness.
What is the difference between gross burn and net burn?
Gross burn is everything the company spends in a month. Net burn is gross burn minus revenue collected in the same month. Runway is always measured against net burn, which is why a company with revenue can spend more than its cash divided by gross burn would suggest.
What is burn multiple and what is a good number?
Burn multiple is net burn divided by net new ARR added in the same period. Under 1 means you add more than a dollar of recurring revenue for every dollar burned. Between 1 and 2 is normal at seed. Over 2 means growth is expensive, and over 3 usually needs a story.
What does default alive mean?
A company is default alive if, on its current growth rate and spend, revenue reaches break-even before the cash runs out. Default dead means it needs a raise or a cut first. The distinction comes from Paul Graham and is the single most useful question to ask about a seed-stage company.
Does the calculator store my numbers?
No. The numbers you type stay in your browser. If you enter an email to see the full result, we store the address with rounded results such as the runway band and health grade, and we email you a code and a link to your result. Nothing else unless you tick the reminders box or reply.